Modifier Keys

Both KeyEvent and MouseEvent are subclasses of java.awt.event.InputEvent. The primary feature InputEvent adds is the ability to test for additional conditions on the event such as whether the ALT key was pressed at the same time as another key, or whether the option key was held while the mouse was dragged. For example, when the shift key is held down, many drawing programs constrain lines to be vertical or horizontal, rectangles to be squares, ovals to be circles, and so on.

The following four methods tell you whether or not the specified key was pressed when this event was sent.

  public boolean isShiftDown()
  public boolean isControlDown()
  public boolean isMetaDown()
  public boolean isAltDown()

All may be invoked on either MouseEvent objects or KeyEvent objects.

There is also a getWhen() method which returns the time the event occurred. This is given as the number of milliseconds since midnight, January 1, 1970, Greenwich Mean Time.

public long getWhen()

The java.util.Date and java.util.Calendar classes have methods you can use to convert this to a date and time. However, most of the time you'll only be concerned with differences in the time between one event and another.

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Copyright 1997, 1998 Elliotte Rusty Harold
Last Modified June 28, 1998